Display panel and method for manufacturing the same

ABSTRACT

A display panel and a method for manufacturing the same are disclosed. The display panel includes: a first substrate, a touch spacer formed on a first substrate, a common electrode formed on the touch spacer, a second substrate opposing the first substrate, a sensing electrode facing the touch spacer on the second substrate and an alignment layer on the sensing electrode or the touch spacer, wherein the alignment layer has a thickness equal to or less than 500Å.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.12/037,583, filed on Feb. 26, 2008, which claims priority from KoreanPatent Application No. 10-2007-0140358, filed on Dec. 28, 2007 in theKorean Intellectual Property Office, all the benefits accruing therefromunder the entire contents of which are incorporated by reference.

BACKGROUND

1. Field of the Invention

The present invention relates to a display panel in which inputsensitivity is improved for efficiently detecting the input coordinatevalues of a touch by a user.

2. Description of the Related Art

A touch screen panel is an information input means which inputsinformation when a user touches a screen. The touch screen panel isinstalled on an image display surface of a display device such as aliquid crystal display (LCD) device, a field emission display (FED)device, a plasma display panel (PDP) device, and an electro luminescence(ELD) device.

The touch screen panel is greatly classified into a capacitive touchscreen panel and a resistive touch screen panel. The capacitive touchscreen panel has one transparent conductive film or glass for storingelectrical charges. When the touch screen panel is touched by, e.g., astylus, a small amount of charge is drawn to a contact point between thestylus and the transparent conductive film. The amount of chargedetected at the contact point is converted into coordinate values. Inthe resistive touch screen panel, if a user touches a screen in a statethat a voltage is applied to two opposite conductive layers, the twoconductive layers contact, and a change in voltage or electrical currentoccurs at the contact point. The change in voltage or electrical currentis detected and converted into coordinate values.

In case of the capacitive touch screen panel, electricity should besupplied to a stylus. For this reason, the resistive touch screen panelof an analog input method, which is constructed integrally with an LCDpanel, is usually used. The resistive touch screen panel may be formedinside an LCD panel in order to prevent brightness of the LCD panel frombeing degraded.

In an LCD panel with an integrated touch screen panel, first touchconductive lines and second touch conductive lines are formed in amatrix form in a thin film transistor (TFT) array substrate so that afirst coordinate value which represents a horizontal contact point and asecond coordinate value which represents a vertical contact point can bedetected. Also, a touch spacer which contacts the first and second touchconductive lines is formed in a color filter array substrate. In case ofa conventional LCD panel with an integrated touch screen panel, there isa problem in that detecting error is frequently caused because the touchsensitivity is low when the touch spacer is contacting the thin filmtransistor array substrate. When too much pressure is used to compensatefor the low sensitivity, the panel reliability degrades.

SUMMARY

Aspects of the invention provide a display panel in which inputsensitivity is improved by controlling the thickness of the alignmentlayer and coordinate values for a touch point can be accuratelydetected. Small touch pressure can be detected easily with this improvedsensitivity and this is very helpful to the reliability of the displaypanel.

In an exemplary embodiment, the present invention provides a displaypanel, including: a touch spacer formed on a first substrate, a commonelectrode formed on the touch spacer, a second substrate opposing thefirst substrate, a sensing electrode facing the touch spacer on thesecond substrate and an alignment layer on the sensing electrode or thetouch spacer, wherein the alignment layer has a thickness equal to orless than 500 Å.

The alignment layer of the area other than the sensing electrode areaand touch spacer area has a thickness of more than 500 Å.

There are at least two touch spacers facing the sensing electrode. Eachof the touch spacer includes an embossing surface or a protrusionportion on the surface.

In another exemplary embodiment, the present invention provides adisplay panel having: a touch spacer formed on a first substrate, acommon electrode formed on the touch spacer, a second substrate opposingthe first substrate, a sensing electrode facing the touch spacer on thesecond substrate and an alignment layer on the sensing electrode or thetouch spacer, wherein the alignment layer has a non-uniform thickness.

There is no alignment layer region on the touch spacer.

There are two or more touch spacers facing the sensing electrode. Eachof the touch spacers includes an embossing surface or a protrusionportion on the surface.

The nearest portion of the touch spacer to the sensing electrode has athinner alignment layer than other portions of the touch spacer.

In another exemplary embodiment, the present invention provides a methodfor manufacturing a display panel including: forming a touch spacer onthe insulating substrate, forming a common electrode on the touch spacerand forming a alignment layer on the common electrode, wherein thealignment layer on the touch spacer has a different thickness than theportions of the alignment layer not on the touch spacer.

The alignment layer on the touch spacer is thinner than the alignmentlayer on the other portions of the alignment layer.

The alignment layer thickness is controlled by an ink jet printingmethod.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or other aspects, features and advantages of the presentinvention will become more apparent from the following detaileddescription when taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a cross-sectional view illustrating a sensing portion in adisplay panel according to an exemplary embodiment of the presentinvention;

FIG. 2 is a plan view of display panel according to an exemplaryembodiment of the present invention;

FIG. 3 is a cross-sectional view taken along line II-II′ of FIG. 2;

FIG. 4 is a cross-sectional view illustrating a sensing portion of adisplay panel according to the first exemplary embodiment of the presentinvention;

FIG. 5 is a cross-sectional view illustrating a sensing portion of adisplay panel according to the second exemplary embodiment of thepresent invention;

FIG. 6 is a cross-sectional view illustrating a sensing portion of adisplay panel according to the third exemplary embodiment of the presentinvention;

FIG. 7 is a cross-sectional view illustrating a sensing portion of adisplay panel according to the fourth exemplary embodiment of thepresent invention.

DETAILED DESCRIPTION

The invention will now be described more fully hereinafter withreference to the accompanying drawings, in which embodiments of theinvention are shown. This invention may, however, be embodied in manydifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. In thedrawings, the size and relative sizes of layers and regions may beexaggerated for clarity.

It will be understood that when an element or layer is referred to asbeing “on,” “connected to” or “coupled to” another element or layer, itcan be directly on, connected or coupled to the other element or layeror intervening elements or layers may be present. In contrast, when anelement is referred to as being “directly on,” “directly connected to”or “directly coupled to” another element or layer, there are nointervening elements or layers present. Like numbers refer to likeelements throughout. As used herein, the term “and/or” includes any andall combinations of one or more of the associated listed items.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “lower” otherelements or features would then be oriented “above” or “upper” relativeto the other elements or features. Thus, the exemplary term “below” canencompass both an orientation of above and below. The device may beotherwise oriented (rotated 90 degrees or at other orientations) and thespatially relative descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a,” “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

Hereinafter, the present invention will be described in detail withreference to the accompanying drawings.

FIG. 1 is a cross-sectional view illustrating a sensing portion in adisplay panel according to an exemplary embodiment of the presentinvention, FIG. 2 is a plan view of a display panel according to anexemplary embodiment of the present invention and FIG. 3 is across-sectional view taken along line II-II′ of FIG. 2.

Referring to FIGS. 1 to 3, the display panel according to an exemplaryembodiment of the present invention includes an upper substrate 101 anda lower substrate 201 with a liquid crystal layer interposedtherebetween.

The upper substrate 101 includes a black matrix 110 for preventing alight leakage, a color filter layer 120 for realizing a color image, anovercoat layer 130 for mitigating a step difference between the blackmatrix 110 and the color filter layer 120, and a common electrode 150for applying a common voltage to the liquid crystal layer, which aresequentially formed on an upper substrate 101.

The upper substrate 101 may be made of a transparent insulating materialsuch as plastic so that it can be smoothly pushed when a user touchesits surface. And the upper substrate 101 may be made of a transparentinsulating material such as glass.

The black matrix 110 is formed to overlap a TFT. A gate line 210, a dataline 240 and first and second touch conductive lines 215 and 245 areformed on the second substrate in order to prevent light from beingemitted through regions where liquid crystal molecules can not becontrolled. To this end, the black matrix 110 is made of an opaqueorganic material or an opaque metal.

The color filter layer 120 includes red (R), green (G) and blue (B)color filters to create various colors. The red (R), green (G) and blue(B) color filters create red, green and blue colors by absorbing andtransmitting light of a certain wavelength through red, green and bluepigments contained therein, respectively. At this time, various colorscan be realized by an additive color mixture of the red (R), green (G)and blue (B) light which pass through the red (R), green (G) and blue(B) color filters.

The overcoat layer 130 is made of a transparent organic material forstep coverage and insulation of the common electrode 150. The overcoatlayer 130 also serves to protect the color filter layer 120 and theblack matrix 110.

The common electrode 150 is formed on the overcoat layer 130. The commonelectrode 150 is made of a transparent conductive metal such as indiumtin oxide (ITO) or indium zinc oxide (IZO). The common electrode 150forms an electrical field for driving the liquid crystal layer togetherwith a pixel electrode 260 by applying a common voltage to the liquidcrystal layer as the pixel electrode 260 applies a pixel voltage to theliquid crystal layer.

The first substrate further includes a touch spacer 141 formed betweenthe overcoat layer 130 and the common electrode 150. That is, the touchspacer 141 is formed on the overcoat layer 130 and is covered with thecommon electrode 150. The touch spacer 141 has a predetermined height,i.e., a convex shape so that the common electrode 150 contacts first andsecond sensing electrodes 270 and 280 of the second substrate when asurface of the upper substrate 101 is touched by a user's finger or astylus pen. A predetermined gap is kept between the touch spacer 141 andthe first and second sensing electrodes 270 and 280 until a user touchesa surface of the upper substrate 101. Also, when a user touches asurface of the upper substrate 101, the touch spacer 141 has the commonelectrode 150 to contact the first and second sensing electrodes 270 and280 so that the contact point can be detected.

Preferably, the touch spacer 141 is made of a conductive material sothat a voltage or an electrical current can be applied between thecommon electrode 150 and the first and second sensing electrodes 270 and280 when the common electrode 150 gets damaged.

An alignment layer 160 to orientate liquid crystal molecules is formedon the common electrode 150. The alignment layer may be made of anorganic material or inorganic material. The thickness of the alignmentlayer 160 may be equal to or less than 500A for better detecting thecurrent flow when the touch spacer 141 contacts the sensing electrode270 and 280 in the second substrate. As the thickness of the alignmentlayer, which is made from an insulating material, becomes thicker, thetouch sensitivity of the touch spacer 141 and the sensing electrodedegrades. This causes a touch sensing error. If this touch sensing erroroccurs, the user will push with extra pressure on the panel, and if thisextra pressure is repeated, the touch spacer 141 and the sensingelectrode 270 and 280 will be damaged and may collapse. Thus, thereliability of the display panel may degrade.

According to test results, when the thickness of the alignment layer is500 Å and the thickness of the glass substrate is 0.5 mm, a touchpressure of even 10˜60 gf is detected. But when the thickness of thealignment layer is 1000 and the thickness of the glass substrate is 0.2mm thin glass, a touch pressure of 70˜700 gf is needed to detect thetouches.

The second substrate includes the gate line 210, the first touchconductive line 215, the data line 240, the second touch conductive line245, the TFT, the pixel electrode 260, and the first and second sensingelectrodes 270 and 280 which are formed on a lower substrate 201.

The gate line 210 is formed in the lower substrate 201 in a firstdirection, e.g., a transverse direction. The gate line 210 may have asingle-layer structure or a multi-layer structure made of molybdenum(Mo), niobium (Nb), copper (Cu), aluminum (Al), chromium (Cr), silver(Ag), tungsten (W), titanium (Ti) or their alloy. A gate electrode 211extends from the gate line 210 near a crossing point of the gate line210 and the data line 240.

The first touch conductive line 215 is formed in the first directionparallel with the gate line 210 and is separate from the gate line 210.The first touch conductive line 215 may be made of the same material asthe gate line 210.

The data line 240 is formed in the lower substrate 201 in a seconddirection perpendicular to the first direction, e.g., a verticaldirection. The data line 240 crosses the gate line 210. The data line240 may have a single-layer structure or a multi-layer structure made ofMo, Nb, Cu, Al, Cr, Ag, titanium (Ti), or other alloys.

The second touch conductive line 245 is formed in the second directionparallel with the data line 240 and is apart from the data line 240. Thesecond touch conductive line 245 may be made of the same material as thedata line 240.

The TFT performs a switching operation in response to a gate signaltransmitted from the gate line 210 so that a pixel voltage signal of thedata line 240 may be charged and maintained in the pixel electrode 260.To this end, the TFT includes the gate electrode 211 extending from thegate line 210, a source electrode 241 extending from the data line 240,and a drain electrode 243 apart from the source electrode 241 andelectrically connected to the pixel electrode 260.

The TFT further includes a gate insulating layer 220 and a semiconductorlayer 230. The gate insulating layer 220 is formed over the wholesurface of the lower substrate 201 to cover the gate electrode 211. Thesemiconductor layer 230 is formed on a portion of the gate insulatinglayer 220 above the gate electrode 211 to form a channel between thesource electrode 241 and the drain electrode 243.

The semiconductor layer 230 includes an active layer 231 and an ohmiccontact layer 233. The active layer 231 is formed to have a channelbetween the source and drain electrodes 241 and 243, overlapping thegate electrode 211. The ohmic contact layer 233 is formed on the activelayer 231 for ohmic contact with the data line 240 and the source anddrain electrodes 241 and 243.

The second substrate 200 further includes a passivation film 250 formedover the whole surface of the lower substrate 201. The passivation film250 is made of an inorganic insulating material, such as silicon nitride(SiNx) or silicon oxide (SiOx), or an organic insulating material, suchas acrylic, polyimide or benzocyclobutene (BCB). The passivation film250 may have a single-layer structure or a multi-layer structure made ofan organic insulating material or/and an inorganic insulating material.The passivation film 250 is formed to cover the TFT and the gateinsulating layer 220, thereby insulating the TFT 247 from the pixelelectrode 260.

The passivation film 250 has first to third contact holes 251 to 253which expose a portion of the drain electrode 243 and portions of thefirst and second touch conductive lines 215 and 245, respectively. Thefirst to third contact holes 251 to 253 are formed by etchingcorresponding portions of the passivation film 250 through a maskprocess.

The pixel electrode 260 is formed on the passivation film 250. The pixelelectrode 260 is electrically connected to the drain electrode 243 ofthe TFT 247 via the first contact hole 251. The pixel electrode 260 ismade of a transparent conductive material such as ITO, IZO, indium tinzinc oxide (ITZO), or tin oxide (TO).

The first sensing electrode 270 includes a first electrode contactportion 271 which electrically contacts the first touch conductive line215 and a first electrode extending portion 272 which extends from thefirst electrode contact portion 271. The second sensing electrode 280includes a second electrode contact portion 281 which electricallycontacts the second touch conductive line 245 and a second electrodeextending portion 282 which extends from the second electrode contactportion 281. The first and second electrode extending portions 272 and282 have various shapes. The first and second electrode extendingportions 272 and 282 may be alternately formed or symmetrically formedas if they engage each other.

The first electrode contact portion 271 of the first sensing electrode270 is electrically connected to the first touch conductive line 215 viathe second contact hole 252 which penetrates the passivation film 250and the gate insulating layer 220. The first electrode extending portion272 of the first sensing electrode 270 is formed on the passivation film250 in a predetermined pattern to face the second sensing electrode 280.

The second electrode contact portion 281 of the second sensing electrode280 is electrically connected to the second touch conductive line 245via the third contact hole 253 which penetrates the passivation film250. The second electrode extending portion 282 of the second sensingelectrode 280 is formed on the passivation film 250 in a predeterminedpattern to face the first sensing electrode 270. Here, the secondelectrode extending portion 282 is formed on the passivation film 250 atthe same height as the first electrode extending portion 272 of thefirst sensing electrode 270. Therefore, when the panel is touched, thetouch spacer 141 equally contacts the first and second sensingelectrodes 270 and 280.

The alignment layer 290 is formed on the sensing electrodes 270 and 280and pixel electrode 260. The alignment layer 290 is in this embodimentof the invention is the uppermost layer in the second substrate and isevenly formed to prevent disorientation of the liquid crystal molecules.The alignment layer 290 may be made of an inorganic material or organicmaterial. As explained above, the thickness of the alignment layer maybe equal to or less than 500 □. This is to better detect the currentwhen the touch spacer contacts the sensing electrodes 270 and 280. Whenthe thickness of the alignment layer, which is an insulating material,is thicker, the sensing signal is less likely to be detected bycontacting the touch spacer 141 and the sensing electrode. This maycause a touch sensing error.

In the display panel according to the exemplary embodiment of thepresent invention, when the upper substrate 101 is touched by a user'sfinger or a stylus pen, the first and second contact electrodes 270 and280 contact through the touch spacer 141, so that a resistance valuevaries depending on a contact position. Since an electrical current orvoltage depends on the varied resistance value, the detected electricalcurrent or voltage is outputted as a horizontal coordinate signalthrough the first touch conductive line 215 and as a vertical coordinatesignal through the second touch conductive line 245. The outputtedcoordinate signals are converted into coordinate values by a drivingcircuit, so that a command or an application program corresponding tothe measured coordinate values is executed.

Various forms of touch spacers and various alignment layers areexplained below referring to the FIGS. 4 to 7.

FIG. 4 is a cross-sectional view illustrating a sensing portion in adisplay panel according to the first exemplary embodiment of the presentinvention. Referring to the FIG. 4, the alignment layers 160 and 290 onthe touch spacer 141 and sensing electrodes 270 and 280 are thinner thanthe other portion than the touch spacer and sensing electrodes. Thecontact points, which are on the touch spacer and sensing electrodeshaving a touch event, are covered by thin alignment layer having athickness equal to or less than 500 Å. Alternatively, the otherportions, not including the touch spacer and sensing electrodes, have athicker alignment layer than the portion on the touch spacer and thesensing electrodes. This thin alignment layer on the touch spacer andthe sensing electrodes improve the contact between the touch spacer andthe sensing electrodes, so the sensitivity of the touch event isimproved. For example, when the alignment layer is formed, an ink jetprinting method may be used. On the touch spacer and the sensingelectrode, the thickness of the alignment layer equal to or less than500 Å is formed and on the other portions, not including the touchspacer and the sensing electrode, the thickness of the alignment layerlager than 500 Å, e.g. 1000 Å, is formed by ink jet printing method insome embodiments of the invention.

FIG. 5 is a cross-sectional view illustrating a sensing portion in adisplay panel according to the second exemplary embodiment of thepresent invention. Referring to FIG. 5, the touch spacer includes morethan two columns. Because the touch spacer facing the sensing electrodes270 and 280 includes more than two columns, the touch spacer contactsthe smaller area of sensing electrodes 270 and 280 compared to the firstembodiment in the FIG. 4. In the second embodiment of the invention, thetouch spacer 141 portion has some peaks and valleys. When the commonelectrode 150 and the alignment layer 160 is formed on more than twocolumns, the alignment layer on the top of the columns will be thinnerthan the other area if the alignment layer is formed using an organicmaterial, e.g. polyimide solution. The liquid (organic material) willflow according to the peaks and valleys on the columns. Thus, thealignment layer 160 on the top of touch spacer 141 may be thinner thanthe other portion. This improves the detection of a touch point andimproves the sensitivity of a touch event. In FIG. 5, the alignmentlayer is drawn to have the same thickness on the touch spacer 141, butactually the alignment layer on the touch spacer 141 may have anon-uniform thickness or thinner thickness portion or there may be noalignment layer region on the touch spacer 141. In FIG. 5, the columnsof touch spaer 141 are drawn as having flat top surfaces, but in someembodiments of the invention the top surfaces of the columns may berounded. The thickness of the alignment layer 160 may be equal to orless than 500. The alignment layer is formed using a coating made of apolymer like a polyimide, ink jet printing method, etc. Using an organicliquid material in a configuration having multiple columns allows thefluid to flow through the peaks and valleys of the columns. Thus, thethickness of the alignment layer is controlled easily which improves thetouch sensitivity.

FIG. 6 is a cross-sectional view illustrating a sensing portion of adisplay panel according to the third exemplary embodiment of the presentinvention. Referring to the FIG. 6, the touch spacer 141 has anembossing surface. The touch spacer 141 having a embossing surface isformed and the common electrode 150 is formed thereon and the alignmentlayer 160 is formed. The alignment layer 161 on the embossing surfacemay have a different thicknesses according to the embossing surface ofthe touch spacer 141. On the convex portion (nearest to the sensingelectrode in the second substrate), the alignment layer may be thinnerthan the concave portion of the surface of the touch spacer 141. Thedifference in the thickness of the alignment layer is caused from theembossing surface of the touch spacer 141. The liquid organic materialwill flow through the inclination of the embossing surface of the touchspacer 141. On the convex portion (the utmost portion of the touchspacer), a very thin alignment layer or no alignment layer at allremains except on the concave portion. This thinner alignment layerhelps the touch spacer to better contact the sensing electrodes 270 and280. Thus more current may flow by the contact improving the touchsensitivity. In the FIG. 6, in some embodiments of the invention theremay be no alignment layer portion on the convex portion of the touchspacer.

FIG. 7 is a cross-sectional view illustrating a sensing portion of adisplay panel according to the fourth exemplary embodiment of thepresent invention. Referring to FIG. 7, the touch spacer 141 in thisembodiment of the invention has a protrusion on the surface. Theprotrusion is near the sensing electrodes 270 and 280. The protrusionmay contact the sensing electrodes 270 and 280. If an organic liquidmaterial (alignment layer material) is used as a coating, the fluidflows down through the protrusion. On the utmost surface of the touchspacer, the thickness of alignment layer 160 is thinner than otherportions of the touch spacer after the organic fluid flows down throughthe protrusion. In other words, the thickness of layer on the protrusivetouch spacer in not uniform. In other embodiments of the invention,there may be no alignment layer on the top surface of the protrusion.This thinner, non-uniform alignment layer 141 or no alignment layer 141on the touch spacer improves the touch sensitivity. With this thinneralignment layer, a smaller pressure touch can be detected. The thicknessof the alignment layer 160 on the touch spacer 141 may be 500 Å and inother portions may be larger than 500 Å.

A method for manufacturing an LCD panel according to an exemplaryembodiment of the present invention is described below.

The method for manufacturing an LCD panel according to an exemplaryembodiment of the present invention includes forming a first substrate(i.e., color filter array substrate) and forming a second substrate(i.e., TFT array substrate).

As shown in FIG. 3, a black matrix 110 is formed on an upper substrate101.

The black matrix 110 is formed such that an opaque organic materiallayer or an opaque metal layer is deposited on the upper substrate 101and is patterned by a photolithography process and an etching process.The black matrix 110 is formed at a predetermined width to preventopaque metal patterns of the second substrate from being seen. The uppersubstrate 101 is made of a transparent insulating material such asplastic so that it can be smoothly pushed when its surface is touched.

A color filter layer 120 is formed on the upper substrate 101 having theblack matrix 110 as shown in FIG. 3. The color filter layer 120 isformed such that red (R), green (G) and blue (B) color filters aresequentially formed by a photolithography method. The color filters maybe formed by an ink jet method.

Next, as shown in FIG. 3, an overcoat layer 130 is formed over the wholesurface of the upper substrate 101 to cover the black matrix 110 and thecolor filter layer 120.

The overcoat layer 130 is formed at a predetermined thickness to protectthe color filter layer 120 and to obtain excellent step coverage when acommon electrode 150 is formed. The overcoat layer 130 may be formed bydepositing acrylic resin using, for example, a spin coating technique.

Then, as shown in FIG. 1, a touch spacer 141 is formed on the overcoatlayer 130 by using a conductive polymer.

In order to form the touch spacer 141, an organic layer is depositedover the whole surface of the upper substrate 101. A photoresist iscoated on the organic layer and is subjected to a light exposure processand a development process of a photolithography process to thereby forma photoresist pattern. The organic layer is patterned by an etchingprocess using the photoresist pattern as a mask, thereby forming thetouch spacer 141. The organic layer may be formed using a photosensitiveorganic layer without a photoresist. The organic layer may be formed byusing an inkjet printing technique.

As shown in FIGS. 4, 5, 6 and 7, the touch spacer may be made in variousforms. In FIG. 5, there is a need for a mask pattern that corresponds tothe multiple columns for making a touch spacer having more than twocolumns. A UV exposure is then applied. In FIGS. 6 and 7, the touchspacer is formed by a slit mask pattern or a half-tone mask pattern.

Subsequently, as shown in FIGS. 1 and 3, the common electrode 150 isformed over the whole surface of the upper substrate 101 to cover theovercoat layer 130 and the touch spacer 141.

In more detail, a transparent conductive material layer is depositedover the whole surface of the upper substrate 101 to cover the overcoatlayer 130 and the touch spacer 141 by using, for example, a sputteringtechnique. The transparent conductive material layer is made of atransparent conductive material such as ITO or IZO. The transparentconductive material layer is patterned into the common electrode 150 bya photolithography process and an etching process using a mask.

Next, as shown in FIGS. 1 and 3, an alignment layer is formed on thecommon electrode 150. The alignment layer may be made of an inorganicmaterial or an organic material. If an organic material is used, thealignment layer can be formed using a roll coating printing method, aspin coating method, an ink jet printing method, etc. In one embodimentof this invention, an Ink jet printing method is used for controllingthe thickness of the alignment layer on the touch spacer 141 and thesensing electrodes 270 and 280. On the touch spacer, the alignment layeris printed with a thickness of equal or less than 500 Å. When thealignment layer is formed by a coating method, a coated organic materialis flown down through (according to) the peaks and valley of thesubstrate, such as on the touch spacer 141 having an embossing surface,more than two columns, or a protrusion surface. The shape of the touchspacer helps the organic fluid material flow down easily. Thus, thethickness of the alignment layer is controlled.

The steps of forming the second substrate are described below in detailwith reference to FIGS. 1 and 3.

A gate metal pattern having a gate line 210, a gate electrode 211 and afirst touch conductive line 215 is formed on a lower substrate 201. Thegate metal pattern is formed such that a gate metal layer is depositedby a deposition technique such as a sputtering technique and is thenpatterned by a photolithography process and an etching process. Thelower substrate 210 is made of a transparent insulating material such asglass or plastic.

The gate line 210 is formed in a first direction, and the gate electrode211 extends from the gate line 210. The first touch conductive line 215is formed in the first direction parallel with the gate line 210. Thefirst touch conductive line 215 is apart from the gate line 210. Forexample, the first touch conductive line 215 is at a distance of about 5μm from the gate line 210.

Then, as shown in FIG. 3, a gate insulating layer 220 is formed over thewhole surface of the lower substrate 201 having the gate metal patternby using a plasma enhanced chemical vapor deposition (PECVD) technique.The gate insulating layer 220 is formed by depositing an insulatingmaterial such as silicon nitride (SiNx) or silicon oxide (SiOx) over thewhole surface of the lower substrate 201. The gate insulating layer 220is formed to cover the gate metal pattern formed on the lower substrate201, thereby electrically insulating the gate metal pattern.

As shown in FIG. 3, a semiconductor layer 230 includes an active layer231. An ohmic contact layer 233 is formed on a portion of the gateinsulating layer 220 over the gate electrode 211. The active layer 231is formed such that a polysilicon layer or an amorphous silicon layer isdeposited and patterned by a photolithography process and an etchingprocess, and the ohmic contact layer 233 is formed such that a dopedpolysilicon layer or a doped amorphous silicon layer is deposited andpatterned by a photolithography process and an etching process.

Subsequently, as shown in FIGS. 1 to 3, a data metal pattern having adata line 240, a source electrode 241, a drain electrode 243, and asecond touch conductive line 245 is formed on the lower substrate havingthe semiconductor layer 230.

In more detail, the data metal pattern is formed such that a metal layeris deposited on the lower substrate 201 having the semiconductor layer230 and patterned by a photolithography process and an etching process.

The data line 240 is formed to cross the gate line 210. One side of thedrain electrode 243 faces the source electrode 241, and the other sideis electrically connected to the pixel electrode 260 to have a widerarea on one side. In some embodiments of the invention, The sourceelectrode may be formed in a letter “U” to surround the drain electrode.

As shown in FIGS. 1 and 2, a passivation film 150 is formed over thewhole surface of the lower substrate 201. First to third contact holes251 to 253 are formed in the passivation film 250.

The passivation film 250 is formed over the whole surface of the lowersubstrate 201 by using a deposition technique such as a PECVD techniqueor a spin coating technique. The first and third contact holes 251 and253 are formed by a photolithography process and an etching processusing a mask to penetrate the passivation film 250. At the same time,the second contact hole is formed to penetrate the passivation film 250and the gate insulating layer 220. The first contact hole 251 exposes aportion of the drain electrode 243. The third contact hole 253 exposes aportion of the second touch conductive line 245, and the second contacthole 252 exposes a portion of the first touch conductive line 215. Thepassivation film 250 may be formed of an inorganic insulating materialsuch as silicon nitride (SiNx) or silicon oxide (SiOx) or an organicinsulating material such as acrylic, polyimide or benzocyclobutene (BCB)

Thereafter, as shown in FIGS. 1 and 3, a pixel electrode 260 and firstand second sensing electrodes 270 and 280 are formed on the passivationfilm 250.

More specifically, a transparent conductive material layer such as ITO,IZO or TO is deposited on the passivation film 250 by using a depositiontechnique such as a sputtering technique and then patterned by aphotolithograph process and an etching process using a mask, therebyforming the pixel electrode 260 in a pixel region.

The first and second sensing electrodes 270 and 280 are formed on thepassivation film 250 at the same height. The first and second sensingelectrodes 270 and 280 are electrically connected to the first andsecond touch conductive lines 215 and 245 via the second and thirdcontact holes 252 and 253, respectively. The first sensing electrode 270includes a first electrode contact portion 271 electrically connected tothe first touch conductive line 215 via the second contact hole 252 anda first electrode extending portion 272 extending toward the secondcontact electrode 280. The second sensing electrode 280 includes asecond electrode contact portion 281 electrically connected to thesecond touch conductive line 245 via the third contact hole 253 and asecond electrode extending portion 282 extending toward the firstsensing electrode 270. The first and second electrode extending portions272 and 282 have many opposite surfaces to each other. A plurality offirst and second electrode extending portions 272 and 282 may be formed.In this instance, the first and second electrode extending portions 272and 282 are alternately or symmetrically formed as if they engage eachother. The first and second electrode extending portions 272 and 282 areformed on the passivation film 250 at the same height.

The first and second sensing electrodes 270 and 280 may be formed in apredetermined pattern form.

Next, as shown in FIGS. 1 and 3, an alignment layer is formed on thepixel electrode 260. The alignment layer may be made of an inorganicmaterial or organic material. If an organic material is used, thealignment layer is formed using a roll coating printing method, a spincoating method, an ink jet printing method, etc. In this embodiment ofthe invention, an ink jet printing method is used for controlling thethickness of alignment layer on the sensing electrodes 270 and 280. Onthe sensing electrode, the alignment layer is printed with a thicknessequal to or less than 500 Å.

Next, the first substrate and the second substrate are attached and aliquid crystal is interposed. The liquid crystal may be dropped on thefirst substrate or the second substrate by one drop filing method andthen the two substrates may be attached.

1. A display panel, comprising: a first substrate; a touch spacer on thefirst substrate; a common electrode on the touch spacer; a secondsubstrate opposing the first substrate; a sensing electrode facing thetouch spacer on the second substrate; an alignment layer on the sensingelectrode or the touch spacer, wherein the alignment layer has anon-uniform thickness.
 2. The display panel of claim 1, wherein there isno alignment layer region is on the touch spacer.
 3. The display panelof claim 2, wherein the touch spacer facing the sensing electrode has atleast two columns.
 4. The display panel of claim 3, wherein the nearestportion of the touch spacer to the sensing electrode has a thinneralignment layer than other portions of the alignment layer.
 5. Thedisplay panel of claim 2, wherein the touch spacer has an embossingsurface.
 6. The display panel of claim 5, wherein the nearest portion ofthe touch spacer to the sensing electrode has a thinner alignment layerthan other portions of the alignment layer.
 7. The display panel ofclaim 2, wherein the touch spacer has a protrusion portion on thesurface.
 8. The display panel of claim 7, wherein the nearest portion ofthe touch spacer to the sensing electrode has a thinner alignment layerthan other portions of the alignment layer.
 9. The display panel ofclaim 1, wherein the touch spacer facing the sensing electrode has atleast two columns.
 10. The display panel of claim 9, wherein the nearestportion of the touch spacer to the sensing electrode has a thinneralignment layer than other portions of the alignment layer.
 11. Thedisplay panel of claim 1, wherein the touch spacer has an embossingsurface.
 12. The display panel of claim 11, wherein the nearest portionof the touch spacer to the sensing electrode has a thinner alignmentlayer than other portions of the alignment layer.
 13. The display panelof claim 1, wherein the touch spacer has a protrusion portion on thesurface.
 14. The display panel of claim 13, wherein the nearest portionof the touch spacer to the sensing electrode has a thinner alignmentlayer than other portions of the alignment layer.
 15. A method formanufacturing a display panel comprising: forming a touch spacer on aninsulating substrate; forming a common electrode on the touch spacer;forming an alignment layer on the common electrode or the touch spacer,wherein the alignment layer has a non-uniform thickness.
 16. The methodof claim 15, herein there is no alignment layer region is on the touchspacer.
 17. The method of claim 15, wherein the alignment layerthickness is controlled by an ink jet printing method.